A novel multi-parameter assay to dissect the pharmacological effects of different modes of integrin L2 inhibition in whole blood

作者:Welzenbach Karl; Mancuso Riccardo V; Kraehenbuehl Stephan; Weitz Schmidt Gabriele*
来源:British Journal of Pharmacology, 2015, 172(20): 4875-4887.
DOI:10.1111/bph.13256

摘要

Background and PurposeThe integrin L2 plays central roles in leukocyte adhesion and T cell activation, rendering L2 an attractive therapeutic target. Compounds with different modes of L2 inhibition are in development, currently. Consequently, there is a foreseeable need for bedside assays, which allow assessment of the different effects of diverse types of L2 inhibitors in the peripheral blood of treated patients. Experimental ApproachHere, we describe a flow cytometry-based technology that simultaneously quantitates L2 conformational change upon inhibitor binding, L2 expression and T cell activation at the single-cell level in human blood. Two classes of allosteric low MW inhibitors, designated I and / I allosteric L2 inhibitors, were investigated. The first application revealed intriguing inhibitor class-specific profiles. Key ResultsHalf-maximal inhibition of T cell activation was associated with 80% epitope loss induced by I allosteric inhibitors and with 40% epitope gain induced by / I allosteric inhibitors. This differential establishes that inhibitor-induced L2 epitope changes do not directly predict the effect on T cell activation. Moreover, we show here for the first time that / I allosteric inhibitors, in contrast to I allosteric inhibitors, provoked partial downmodulation of L2, revealing a novel property of this inhibitor class. Conclusions and ImplicationsThe multi-parameter whole blood L2 assay described here may enable therapeutic monitoring of L2 inhibitors in patients' blood. The assay dissects differential effect profiles of different classes of L2 inhibitors.

  • 出版日期2015-10